 /*******************************************************************************
  * Copyright (c) 2004, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.internal.preferences;

 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.osgi.service.prefs.BackingStoreException;
 import org.osgi.service.prefs.Preferences;

 /**
  * @since 3.0
  */
 public class RootPreferences extends EclipsePreferences {

     /**
      * Default constructor.
      */
     public RootPreferences() {
         super(null, ""); //$NON-NLS-1$
 }

     /*
      * @see org.osgi.service.prefs.Preferences#flush()
      */
     public void flush() throws BackingStoreException {
         // flush all children
 BackingStoreException exception = null;
         String [] names = childrenNames();
         for (int i = 0; i < names.length; i++) {
             try {
                 node(names[i]).flush();
             } catch (BackingStoreException e) {
                 // store the first exception we get and still try and flush
 // the rest of the children.
 if (exception == null)
                     exception = e;
             }
         }
         if (exception != null)
             throw exception;
     }

     /*
      * @see EclipsePreferences#getChild(String, Plugin)
      */
     protected synchronized IEclipsePreferences getChild(String key, Object context) {
         Object value = null;
         IEclipsePreferences child = null;
         if (children != null)
             value = children.get(key);
         if (value != null) {
             if (value instanceof IEclipsePreferences)
                 return (IEclipsePreferences) value;
             //lazy initialization
 child = PreferencesService.getDefault().createNode(key);
             addChild(key, child);
         }
         return child;
     }

     /*
      * @see EclipsePreferences#getChildren()
      */
     protected synchronized IEclipsePreferences[] getChildren() {
         //must perform lazy initialization of child nodes
 String [] childNames = childrenNames();
         IEclipsePreferences[] childNodes = new IEclipsePreferences[childNames.length];
         for (int i = 0; i < childNames.length; i++)
             childNodes[i] = getChild(childNames[i], null);
         return childNodes;
     }

     /*
      * @see Preferences#node(String)
      */
     public Preferences node(String path) {
         return getNode(path, true); // create if not found
 }

     public Preferences getNode(String path, boolean create) {
         if (path.length() == 0 || (path.length() == 1 && path.charAt(0) == IPath.SEPARATOR))
             return this;
         int startIndex = path.charAt(0) == IPath.SEPARATOR ? 1 : 0;
         int endIndex = path.indexOf(IPath.SEPARATOR, startIndex + 1);
         String scope = path.substring(startIndex, endIndex == -1 ? path.length() : endIndex);
         IEclipsePreferences child;
         if (create) {
             child = getChild(scope, null);
             if (child == null) {
                 child = new EclipsePreferences(this, scope);
                 addChild(scope, child);
             }
         } else {
             child = getChild(scope, null, false);
             if (child == null)
                 return null;
         }
         return child.node(endIndex == -1 ? "" : path.substring(endIndex + 1)); //$NON-NLS-1$
 }

     /*
      * @see org.osgi.service.prefs.Preferences#sync()
      */
     public void sync() throws BackingStoreException {
         // sync all children
 BackingStoreException exception = null;
         String [] names = childrenNames();
         for (int i = 0; i < names.length; i++) {
             try {
                 node(names[i]).sync();
             } catch (BackingStoreException e) {
                 // store the first exception we get and still try and sync
 // the rest of the children.
 if (exception == null)
                     exception = e;
             }
         }
         if (exception != null)
             throw exception;
     }
 }

